The invention relates to a method for utilization of braking energy generated by rail vehicles which comprise regenerative braking means for converting braking energy of said rail vehicles into electrical energy, in particular when said rail vehicles brake and/or decelerate at a railway station or close thereto. The present invention further relates to an energy consumption and distribution system for consumption and distribution of such electrical energy generated by regenerative braking means of rail vehicles.
Systems for recovering braking energy of rail vehicles are known, for instance from EP 1 985 490 which describes an energy recovery system comprising a rail vehicle on a track, e.g. a train vehicle, which is electrically connected, via a pantograph, to a power supply line to collect electrical power there from. The rail vehicle is provided with an electric motor adapted to rotate the wheels of the rail vehicle when provided with electric power. During braking of the rail vehicle the motor may be operated as a generator for generating electrical energy, in which case the electrical energy generated during braking is returned to the power supply line. The known system further comprises power supply stations which are arranged at predetermined locations along the track, for supplying electrical energy from an electrical grid to the rail vehicle, and for receiving electrical energy from the rail vehicle during braking and transporting this energy back to the electrical grid. In an embodiment, a portion of the energy which is generated during braking of a rail vehicle is directly used for powering acceleration of another rail vehicle and the remaining portion of regenerated energy is transported, via the power supply stations, back to the electrical grid.
A drawback of the known system is that, in order to convert the electrical energy generated during braking of a rail vehicle into a form of energy suitable for transport within the electrical grid, a complex voltage regulation system and/or power converter is required at the power supply stations. Power supply stations are typically adapted for receiving electrical energy from the electrical grid at a first voltage, for instance a voltage of 10.000 V, at which electrical energy is transported within the electrical grid, and for converting this energy into electrical energy suitable for driving a rail vehicle at a substantially lower second voltage, e.g. a voltage of 1.500 V. During braking, the rail vehicle generates electrical energy at a third voltage which is between the first voltage and the second voltage, e.g. the rail vehicle generates a voltage in a range of about 1.600-1.900 V during braking. Consequently, besides converting electrical energy from the first voltage to the second voltage, in the known system the power converter and/or voltage regulation system must also be adapted for converting energy from the third voltage to the first voltage.
It is an object of the present invention to provide a more simple method and system for utilization of braking energy of rail vehicles, allowing efficient use thereof.